“Only seven per cent of mammals and four per cent of birds that showed a negative response to climate change are currently considered ‘threatened by climate change and severe weather’ by the International Union for the Conservation of Nature Red List of Threatened Species.”

Associate Professor Watson said the study reviewed the observed impacts of climate change on birds and mammals using a total of 130 studies, making it the most comprehensive assessment to date on how climate change has affected well-studied species.

“The results suggested it is likely that around half the threatened mammals (out of 873 species) and 23 per cent of threatened birds (out of 1272 species) have already responded negatively to climate change,” he said.

Lead author Michela Pacifici, of the Global Mammal Assessment Program at Sapienza University of Rome, said this implied that these species had a high probability of being negatively affected by future climatic changes.

Associate Professor Watson said the study clearly showed that the impact of climate change on mammals and birds had been greatly under-estimated and under-reported.

“This under-reporting is also very likely in less studied species groups. We need to greatly improve assessments of the impacts of climate change on all species right now,” he said.

“We need to communicate the impacts of climate change to the wider public and we need to ensure key decision-makers know significant change needs to happen now to stop species going extinct.